Longitudinal characterization of determinants associated with obesogenic growth patterns in early childhood

Abstract

Background: Longitudinal assessment of the determinants of obesogenic growth trajectories in childhood can suggest appropriate developmental windows for intervention.

Methods: Latent class growth mixture modelling was used to identify body mass index (BMI) z-score trajectories from birth to age 6 years in 994 children from a prospective mother-offspring cohort (Chinese, Indian and Malay ethnicities) based in Singapore. We evaluated the early-life determinants of the trajectories as well as their associations with cardiometabolic risk markers at age 6 years.

Results: Five BMI z-score trajectory patterns were identified, three within the healthy weight range, alongside early-acceleration and late-acceleration obesogenic trajectories. The early-acceleration pattern was characterized by elevated fetal abdominal circumference growth velocity, BMI acceleration immediately after birth and crossing of the obesity threshold by age 2 years. The late-acceleration pattern had normal fetal growth and BMI acceleration after infancy, and approached the obesity threshold by age 6 years. Abdominal fat, liver fat, insulin resistance and odds of pre-hypertension/hypertension were elevated in both groups. Indian ethnicity, high pre-pregnancy BMI, high polygenic risk scores for obesity and shorter breastfeeding duration were common risk factors for both groups. Malay ethnicity and low maternal educational attainment were uniquely associated with early BMI acceleration, whereas nulliparity and obesogenic eating behaviours in early childhood were uniquely associated with late BMI acceleration.

Conclusion: BMI acceleration starting immediately after birth or after infancy were both linked to early cardiometabolic alterations. The determinants of these trajectories may be useful for developing early risk stratification and intervention approaches to counteract metabolic adversities linked to childhood obesity.

Keywords: BMI z-score trajectories; Childhood obesity; group-based trajectory modelling; growth trajectories; mother–offspring cohort; risk factors for childhood obesity.

Figure 1

(a) Post-natal BMI trajectory classes. Differences in (b) birthweight and (c) fetal abdominal circumference velocity (FACV) across BMI trajectory classes. Trajectory modelling revealed five distinct trajectory classes (N = 994). The three stable trajectories, Stable Normal Low (SNL), N = 131 (13.2%), Stable Normal (SN), N = 458 (46.1%), Stable Normal High (SNH), N = 264 (26.6%), stayed within the normal range of BMI [broken lines depict WHO thresholds for overweight (1SD), obesity (2SD) and thinness (–2SD) at age 6 years]. The early-acceleration [EA, N = 58 (5.8%)] trajectory showed BMI acceleration immediately after birth and crossed obesity threshold after 2 years of age. The late-acceleration [LA, N = 83 (8.4%)] trajectory was close the SN trajectory in the first year, started accelerating after age 1 year and was close to the obesity threshold by age 6 years. Mean birthweights (kg, N = 994) of SNH and EA children were higher and those of SNL children were lower than those of SN children. FACV (mm/week, N = 927) between second and third trimesters was higher in EA and SNH classes as compared with SN whereas LA and SNL classes have similar FACV to the SN class. Bonferroni corrected P-values are indicated.

Figure 2

Schematic diagram showing pre- and post-natal risk factors and post-natal behavioural and cardiometabolic assessments associated with early-acceleration and late-acceleration trajectory patterns. Up arrow indicates an increase in risk of being classified into a trajectory class linked to risk factor or an elevated outcome relative to the Stable Normal trajectory pattern.